In recent times electrically controlled, and particularly non-contact controlled appliances have been increasingly used in sanitary arrangements. In this context ever greater efforts are being made to drive these appliances independently of the mains voltage, that is, to provide them with a self-sufficient power source. This not only reduces the cost of the electrical appliance remarkably, but also allows much easier assembly or upgrading where necessary and is not subject to any psychological problems with the user who frequently fears any mains connections in wet areas and thus prefers to forego electrically operated appliances. If the electrically operated appliance is equipped only with a battery or an accumulator, then either the battery has to be changed at regular intervals or the accumulator must be charged up again. If the charge on the battery or accumulator is approaching its end, there is the risk that the appliance will not function properly.
Thus there have been various attempts made in the past to insert regenerative power sources, which obtain their energy from the surroundings in which the sanitary appliance is placed, for recharging an accumulator inside the sanitary appliance or even for directly driving it. Thus for example, the use was proposed of solar cells which are, though, not particularly effective in the frequently not very strongly illuminated spaces in which sanitary appliances are used. They therefore require relatively large surfaces. With any dirtying which might be feared in any such areas, they lose still more of their efficacy. In addition, charging the accumulator in the relatively long periods of darkness is not possible.
It is also known to use Peltier elements for supply of power to sanitary appliances which can, though, only be effective if warm water is available and it is also flowing. If warm water does not flow through the sanitary appliance for a long time, the Peltier elements are no longer adequate as a source of power.
Similar problems arise with mechanical turbines which are set in rotational motion by the flowing water and which drive an electrical generator. An apparatus of this type also presupposes a relatively frequent water flow; when the sanitary appliance stops for a long period, charging of the accumulator does not take place.